This invention relates to a remote controlled pneumatic release device for a load hook which is releasable by pneumatic pressure.
U.S. Pat. No. 4,095,833 describes a pneumatic-controlled releasing hook device for releasing a load after the load has been lifted and moved to a different location, without requiring manual manipulation of the hook to disengage it from the load. The releasing mechanism in the hook is operated by compressed air whereby a compressed air line must follow alongside the lifting cable or chain to a compressed air reservoir in the crane or other lifting device. Such an air line is the cause of considerable trouble in the routine operation of the crane.
There is a need for a less complicated and more troublefree mechanism for releasing such load hooks. In particular, it is desired to eliminate the air line extending from the crane hook alongside the lifting cable back to the compressed air reservoir, and to provide an improved type of remote control for the hook release function.